Step mechanism



July 12,A 1932.

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ATTORNEYS,

Patented July 12, 1932 assises i UNITED STATES PATENT o-FFlcr.

JOHN S. MCWHIRTEB, QF SOUTHQEORT, CONNECTICUT, -ASSIGNOR TO NATIONALPNEU- MATIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIAs'rEP MECVHANISM i Application filed February 26, 1931. Serial No.518,481.

This invention relates to improvements in step mechanism for vehicles.

"One of the objects of this invention is the provisionwith aA folding orsliding step for vehicles, of means controlledfby the step forpreventing its operation when a person is standing on the step or iscaught on the step'.

A further object of this invention is to pro-y vide a combinationincluding a vpower operated step controlledfrom a. point remote from thestep, and means controlled bypressure on the step tread to prevent itsactuation by the power device.

A still further objectV of this invention is the provision of a foldingstep used particularly in connection with the` exit 'way vof a vehiclewhich is normally remote from the point of control.

Another object of this invention is the pro'- vision of a strepstructure which is power actuated between two predetermined andadjustable limitsl of' movement and` arranged so that the tread ofthestep may be moved a short distance under pressure beyond which it ismoved by power.

A still further object of this invention is the provision of poweractuated step tread supporting arms, a treadmovable a short distancewith respect to said arms, anda switch or switches actuated ybytheadditional movementV of the tread.

These andmany otherobjects, as will appear from the followingdisclosureare. secured bymeans of this invention.

This invention resides s-ubstantially inthe combination, construction,arrangement and Y relative location of parts, all as will'be set' forthinthe following description.

Referring to the drawings: i Fig. l is a diagrammatic, and schematicdisclosure with some parts in cross section of the system of thisinventiong.

Fig. 2 is a front elevational view of, the

i step of this invention info lded position;

Fig. 3 is a cross sectional view taken on the line 3-3 of Fig. 2;y j

Fig. 4; is a cross sectional view withlsome parts broken away taken onthe line 4 4 of In modern transportation systemsitis now common practiceto provide vehicles 'and especially buses with-entrance and exit ways.The entrance ways are usually adjacent the vehicle operators station,while the exit ways are remote from that point, as for example, in busesat the rearthereof. Likewise the" s ocalled one-man street carsarekprovided with entrance ways at the front and exit ways at the rear.The operation of the barriers for the entrance and exit ways is eitherunder the control of the operator or under' the control y of treadleplates adjacent the barriers andthe operator. Thus there is a danger,especially in connection with the eXitbarrier that the vehicle operatorattempt to close the exit barrier and its associated step at the time aper son is leaving or entering the vehicle. vThe general object of thisinvention is the provision of affol'ding or otherwise movable stepforthe entrance and exit ways particularly ythe eXit ways of vehicles,which controls the power operating mechanism when pressure is applied tothe step tread. j

This invention is similar in nature to the invention set forth infmycopending application, Serial No. 518,480filed'Feb. 26, 1981.

Referring to the drawings the complete system is shown diagrammaticallyinFig.'1. VThe platform of the vehicle' adjacent-.the eXit way forexample, is shown'at l, from which depends two step supportingbracketsQwhich Supported l are enclosed by a toe board 3. from the brackets 2 forrotation, is the step shaft 4; to which is keyed yfor movementtherewith, the step arms 5. The varms 5V are provided with rearwardlyextending projections 6 to which are secured adjustable bolts 7 forengaging with the step hangers 2, to limit the unfolding or openingmovement ofthe step.

' thereto.

Enclosing each of the arms 5 are the arms 8 in the form of casings asshown to the outer edge of which the tread 9 is secured. The arms 8 arefreely and rotatably supported on shaft 4, so that they may rotatewithrespect Springs 10 are interposed between the tread 9 and the arms 5.Secured to shaft 4 is an arm 11 which is pivotally connected to the rod12 by means of a coupling member 25. Pinned to the rod 12 in spacedrelation p are the -collars 13 between which lie the springs 14 whichlie against a sliding collar 15 which encircles the rod. This collar 15is se-A cured to a piston rod 16 of thedi'ferential arranged kthat Whensolenoid 31 is de-energized the spring41'keeps valve 23 closed andyvalve 40 open, thus connecting the right side Yof the large piston ofengine 17 to atmosphere through pipe 21 and casing 20. In this conditionVfluid pressure acting between the pistons of engine 17 from source 18through pipe 19 keeps the pistons to the right and step arms 5 againsttheir stop 38 (Figs. 2 and 4).

When the solenoid 31 is energized by any means such as the switch 33,current flows from the source 29 through wire 34 and switch 33 to wire32, wire 27, the winding of solenoid 31 and wire 30 to the oppositesideof the current source. vThis causes fluid pressure to How fromsourceV 18 through pipe 22 to casing 20 and past valve 23, which has`vbeen opened by the energize-tion of solenoid31 to` pipe 21 andthe rightside of the largepiston of engine 17, the action of solenoid 21 havingalso closed valve 40 so that fluid pressure does not escape toatmosphere.V VThe action of fluid at the same pressure on both sides ofthe large piston balances the effect of the large piston and piston rod16 is driven to the left,

by the fluid pressure acting'on the small piston. The movement of rod 16tothe left lowers the step arms 5 until they are stopped by bolt7and-hanger 2. j

- The magnet valve constructiony is also 'well konwn in many forms. ptread 9 is a switch 26 arranged so that it will be closed when the tread9 ismoved downvwardlywith respect to the arms 5 against the reaction ofspringlO. The lixed contacts of thisswitch Vare connected by wire 27 toone terminal of the magnet valve 20 and by wire 28to one terminal of thecurrent source 29.

Valve casing 2O con-v tains spring 41, valve 23, and valve 40, all soMounted in the` step The other terminal of the current source isconnected by wire 30 to the other terminal of the magnet valve 20.

When the switch 26 has been closed by pressure on the tread 9, thesolenoid 31 of magnet vvalve 2O4 is held energized', even though switch33 may. be open, thus keeping pressure on the right side of the largepiston of engine 17 and keeping the step in its lowered position.Also,.after switch 33 has opened and` engine 17 has started to raise thestep,` if pressure is 'applied to tread 9, switch 26 will operate and bythe energization of magnet valve 2O cause engine 17 to again lower thestep. i .Y v f The step structure itself is clearly shown in Figs. 2,-'3and 4. As stated, the step operating shaft 4 is rotatably mounted inbrackets 2, `which are supported from the car frame. An arm 11 suitablyconnected to shaft 4 is pivotally connected to the coupling member 25which is attached to the rod 12. The arms 5 which are keyed to the shaft4 for rotation therewithlie within enclosing arms 8 which e are` looselymounted on shaft 4 for rotation about the shaft. Within the tread 9 arethe switches 26 which may be of any suitable construction and arrangedso that the movable memberof the switch projects through they switchcasing into a position to be engaged by the arms 5. The wires lead ffrom these switches and out through a cable 40 Whichis protected by aflexible metal casing 41. I

YAls is clear from F ig.v 2, arms 5 are rearwardly projecting arms towhich are secured the adjustable bolts 7 which engage with therearwardly extending flangesl on the hangers 2. y Figs. 2 and 4 showacollar 35 attached to the shaft 4 and providedwith a projecting lug 36.Formed integral with the brackets 2 is a casing 37 whichv islikewiseprovided with a projectinglug, .in this case number 38. Vlienthe step has been closed vthe lug 36 on collar 35 engages lug `38 on thecasing 37 to prevent the step armsl and their attached barriers frommoving any-further.l Collar 35 is adjustably attached to the shaft sothat the movement of the step to closed position 'may be adjustablycontrolled. Likewise the movement of the step to open position may beadjustably controlled by means of the bolt 7 which engages therearwardly extending lange of the hangers 2. By means of theseadjustable sides it is possible to effect movement of the step betweentwo predetermined liimts. When the step is fully open and pressure isapplied thereto by persons standing on the step the tread rotatesdownwardly on .the shaft 4 with respect toarms 5, compressing spring 10and closing switch 26. The same is true if the steptread should catch onthe clothing of'a person when it iszclosing.

1n, the normal operation of the device switch 33is closed by anysuitable means, such' the vehicle floor so constructed that pressurethereon causes the switch 33 to close, so that pipes 21 and 22 areinterconnected. Fluid pressure is of course continuously supplied to theengine through pipe 19. When pipes 21 and 22 are interconnectedby valve2O fiuid pressure is also supplied to the right hand end of the largecylinder. The pressure being the same on both faces of the large pistonno external effect results and the pressure on the smallerl pistoncauses both pistons which are united to move to the left carrying withit arms 16 and collar 15. vSprings 11i are of such strength that thepressure is transmitted from collar 15 to rod 12 through the left handspring 14 causing the step to move downto full open position. With thisconstruction the pistons can be intentionally set to overtravel, forwhen they overtravel the step moves down to the -full open position andstops, the overtravel of the pistons being taken up by the compressionof spring 14.

It is highly desirable to initially .adjust the pistons with anovertravel, for this overtravel is thus available to take up wear'in thestep operating mechanism as such develops, and this insures full travelof the step. When a person steps on the tread 9 so thatswitch 26 isclosed current also flows from source 29 through switch 26 to holdmagnet valve 2O energized. At this time if switch 33 is opened, magnetvalve 2O remains energized by means of switch 26. Therefore the engine17 will not operate to close the step or even tend to close the step.Thus the operator cann not by accidentally moving his valve 23 topos'tion B cause the step to close while there is any pressure on thetread sufficient to maintain switch 26 closed. As soon, however, as thetread is free, spring 10 moves it upwardly permitting switch 26 to open.As the result magnet valve 20 is -de-energized and the fluid pressure onthe right face of the large piston is again exhausted to atmosphere.rlhe fluid pressure acting between the pistons of engine 17 then drivespiston 16 to .the right and causes the step to close. parent thatovertravel of the pistons has been provided for in the closing of thestep as well in the opening already described.

y Another advantage of the spring connection is that if the vstep shouldstrike the body of a person when moving downwardly, or a persons foot orother object be caught between the step and the car body when lit is`moving upwardly, spring 14 can give so that no injury will result andthe object may be withdrawn by pulling on the step tread.

it is apparent that more than oneswitch may be mounted in the step tread9. Fig. 2 shows two switches 26 mounted in the step tread. lhcre morethan one switch 26 is used, one of the 'switches may be used ashereinbefore described and another switch 26may be used for some otherpurpose, for example able -with respect to. said arms.

It is apv as set forth vin Lmy copendin'g application, Serial No.518,480 filed Feb. 26, 1931.

From the foregoing disclosure it will be Y What I seek to secure byUnited States Letters Patent is: f v

1. A step mechanism of the typedescribed comprising a rotatable stepshaft, arms secured .to said shaft for rotation therewith,

and a Vstep tread mounted on said shaftfor movement therewith andarranged tobemov- 2` A step structure-of the typeV described comprisingsupporting hangers, a shaft rotatably supported in said hangers,'armssecured to said shaft for rotation therewith, a step tread, and meansfor securing the step tread to said shaft to effect combinedmovej' mentof lthe arms and tread and Ito permit movement of the tread with respectto the arms. f j

A step structureqof the type described comprising supporting hangers,^ashaft rotatably mounted in said hangers,;armsse curedl to said shaft`for rotation therewith,

4hollow casings ,enclosing said arms and mounted on said shaft formovement withrespect thereto, Vand a tread mounted on said hollowcasings whereby pressure on'the tread permits movement of the tread andhollow .im ist casings with respect to the arms securedtoy the shaft. i

4. A step structure of the type described comprising `supportinghangers, a shaft rotatably mounted in said hangers, arms secured to saidshaft for rotation therewith, hollow casings enclosing saidarmsl landmounted on said shaft for movement with,

respect thereto, a tread mounted on said hollowarms whereby pressure onthe tread .per` mits movementof the tread and hollow casings with.respect to the arms secured -to the shaft, and resilientimeans betweenthey arms attached to the shaft andv the tread forresisting movement ofthe'tread'with-respect to the varms attached to the shaft.

5. A step mechanism of the typedescribed comprising a rotatablysupported shaft, rigid arms secured tosaid shaft, hollow arms free.-

lay-mounted on said shaft` and enclosing said Y rigid arms, a treadsecuredto'said hollow arms, springs interposed between the tread andsaidrigid arms, and a switch'mechanism mounted on said tread andarranged soas to be closed when-the tread and hollow arms are movedAwith respect to the rigid arms.

`6. A stepfmechanismof the type described comprising a 1rotatablysupported shaft, rigid arms securedto said shaft, hollew arms freelyarms, spring interposed between the tread the rigid arms, and switchmea'ns mountedv and said rigid arms, and adjustable means for limitingthe movement of the rigid arms and shaft at each end of their travel.

7. In a step structure the combination with hangers and a shaftrotatably supported therein, of arms fixed to said shaft', stops forlimiting the movement of the shaft v.in either direction, arms looselymounted on said shaft, and a tread secured to said arms and looselymounted on saidshaft, said tread and arms 1oosely mounted on said shaftcooperating with the arms fixed to said shaft .for limiting the movementof the treadin either direction.- Y.

8. A step structure of the type described comprising the combinationwith hangers, a shaft rotably supported in' said hangers and rigid armsfixed to said shaft, of stops for limiting the movement of the shaft,arms loosely attached to the shaft, a tread mounted'on'said armsv andsprings interposed between said tread and rigid arms to resist movementof the tread with respect `to the rigid arms. f'

9. A step structure of the type described comprising hangers, a shaftrotatably supported in the hangers, rigid arms attached to said shaft,hollow arms looselyk attachedto said shaft, a tread securedto saidVhollow arms, the hollow arms and tread permitting Ybut limiting themovement of the .tread with respect to the rigid arms, springs forresisting the movement of the tread with respect to on the tread sowasto be operated when the tread moves with respect to the rigid arms.

10. A step structure of the type described comprising a rotatable shaft,rigid arms attached to said shaft, stop means for limiting the movementof the shaft and a tread mounted on said shaft and movable withrespect'to thefrigid arms. Y

11. A step structure of the type described comprising a rotatable shaft,rigid arms attached to said shaft, stop means for limiting the movementof the shaft, la tread mounted on said shaft and movable with respect tothe rigid arms, and means for limiting the lmovement of the tread withrespect to the rigid arms.

12. A step 'mechanism as described com-V prising a rotatable shaft, armssecured to said shaft, atread attached to said arms, a motive device,and spring connecting means for connecting the motor device to saidshaft whereby the springs will take up overtravel of the Vmotive device.

'13. Ay step mechanism as described comprising hangers, a shaftrotatably supported in said hangers, rigid arms secured toV said shaft,means for limiting the movement of said shaft in either. direction, atread loosely mounted on said shaft and movable with respect tosaidrigid arms, a motive device and means for connecting the motivedevice to said shaft including springs whereby the parts comprising thestep may be moved manually with respect to the motive device.`

14. In an apparatus of the type described the combination comprising amovable step, motive means for moving said step, a source of energy,means for controllingv the supply of energy from the source to themotive device, and means controlled by the step when pressure is appliedthereto for preventing the supply of energy from the source to themotivedevice.

15. In an apparatusV of the type described the combination comprising afoldingstep including a movable tread, motive means for voperating thestep, va source of energycon-d?,5

nected to said motive means, means for con- A trollingthe supply ofenergy from the source tothe motivevmeans, and meanscontrolled by themovement of the tread forrendering the means for controlling the supplyof energy invfiuid pressure motor, a valve for controlling the supply offluid pressure to the motor, and means controlled by the movement of thetread under a pressure for preventing the motiveV device from beingoperated by move the step to closed position. y 4,

17., In an apparatus of the type described the combination comprisingrotatably supthe valve4 to ported step arms, a tread movable with re,`

spect'to said step arms', a switch mountedyon said tread to be closedwhen it moves with respect to said arms, means for moving said step armsincluding a motivedevice, a source of energy, means for controlling thesupply.

of energy from the source to the motive device, and auxiliary meansconnected Vto said switch for renderingy said controlling meansineffective when the tread is moved spect to the step arms.

with re- 18. A step mechanism as described comffr prising a rotatableshaft, arms secured to said d shaft, a tread supported by said shaft,stop means for limiting the movement of the arms in either direction, amotive device and spring connecting means between the motive device andsaidv shaft wherebywhen said stops become effective over travel of themotive device will be absorbed by said spring connection. d

19. In a mechanism as described the com-` 1 bination of a folding stepcomprising movable i arms and a tread movable with said arms and withrespect thereto under pressure, a motiveV device connected to said stepfor opening and closing it, a source of energy for the motive my hand onthis 31st day of January A. D.,

JOHN S. MGWHIRTER.

